Conventional personal care and household cleaning products are available either as solids or as liquids. Solid cleaning products include bar soap, which can be whipped up into a lather by agitation with hands, or a brush in the case of a shaving soap; or powders which are normally first dissolved in water and then agitated to prepare a lather. Bar soaps and powders may cause unsightly residues on sinks, bath tubs and showers if exposed to water. This also results in waste of products.
Liquid cleaning products are generally available as thick liquids, such as shampoos, shower gels, or liquid soaps, which are difficult to foam and take time, dexterity, and special manipulation to dispense from their containers and to foam and lather.
The use of aqueous post foaming compositions in the form of a gel in personal care products such as shaving creams, toothpaste, and shower gels has been known in the art for several years. However, these products are generally packaged in rigid pressurized aerosol containers such as the Sepro.TM. can or Piston.TM. cans with propellant gases contained therein. Such aerosol containers are expensive to manufacture and ship. The propellants used therein do not form an integral part of the composition and are typically compartmentalized from the product to provide the positive pressure needed to aid in the dispensation of the product. Such containers are known in the industry as barrier packages because they provide the barrier between the extraneous propellants and the composition to be dispensed. The propellant gases released to the atmosphere by use of such containers are increasingly unacceptable environmentally. The aerosol containers for dispensing post foaming gels typically contain these products under pressures ranging from about 308 kPa to about 420 kPa (about 44 psig to about 60 psig) above the atmospheric pressure at ambient temperatures, and dispense about less than four gram/sec of the product at a given time.
Some personal care products like shaving lathers, and mousses are characteristically dispensed as foams and are contained in the pressurized dispensers designed to maintain or increase the inside vapor pressures of the product from about 350 kPa to about 700 kPa (about 50 psig to about 100 psig) and to dispense between about 5 to about 6 grams/sec of the product at a given time.
U.S. Pat. Nos. 4,726,944, and 4,744,979 disclose post foaming liquid compositions which have vapor pressures less than atmospheric pressure at ambient temperatures. These compositions can be poured onto the skin or other surface, rubbed up to 60 seconds to generate foam.
None of the prior art, however, discloses a self foaming aqueous liquid composition that 1) is packagable in a non-pressurized container of barrier material, 2) contains a pressure agent which forms an integral part of the composition, 3) exerts a positive pressure above atmospheric pressure at ambient temperatures when packaged, and 4) is dispensed as a liquid which foams instantaneously on spreading with a single motion and develops into copious foam.
Moreover, none of the prior art discloses a non-pressurized dispenser of a barrier material with a head space, which is not separated from the product by a barrier. The package is capable of 1) containing a self foaming aqueous liquid composition under positive pressure, i.e., vapor pressure of the composition being above atmospheric pressure but below 280 kPa (40 psig) at ambient temperatures, and 2) dispensing varying amounts of the composition in a liquid form by the operation of a positive shut-off valve.